[Coexistence of myelofibrosis and collagen diseases]

Abstract

Hematologic abnormalities are common in association with collagen diseases, specially Systemic Lupus Erythematosus and include anemia, neutropenia, thrombocytopenia with alterations in lymphocyte subpopulations. On the other hand, patients with unexplained fibrosis of the bone marrow (the syndrome of idiopathic myelofibrosis or primary myelofibrosis) have clinical and laboratory evidence of immunologic dysfunction. Clinical findings include the presence of arthritis, vasculitis and erythema nodosum. Laboratory abnormalities include the presence of circulating immune complexes, antinuclear antibodies, positive direct Coombs test, elevated latex fixation and a circulating lupus type anticoagulant. Total hemolytic complement markedly depressed has also been reported. These data suggest that immunologic mechanisms associated with activation of the complement system play an important role in the disease process of some patients with agnogenic myeloid metaplasia with myelofibrosis. A review of the literature revealed that myelofibrosis occurring in the setting of collagen diseases is rare. However, a role for immunologic factors in the pathogenesis of myelofibrosis is also supported by the patients with coincident well defined collagen disease and myelofibrosis. In this report, we present two patients with such an association. Case 1 was a 58-year-old male with a two year duration history of rheumatic arthritis. He had bone erosions on hands, splenomegaly and myelofibrosis. Rheumatoid factor (latex) was positive: 1:2560. He had positive LE cells and hypocomplementemia: 37 CH50/ml (NV 70-150). The patient did not meet criteria for SLE. Case 2 was a 36-year-old female admitted because of dyspnea and fever. Diagnosis of myeloid metaplasia with myelofibrosis and progressive systemic sclerosis had been made four years before hand.(ABSTRACT TRUNCATED AT 250 WORDS)